Griffin David, Wittmann Sylvie, Guo Fei, Nimmanapalli Ramadevi, Bali Purva, Wang Hong Gang, Bhalla Kapil
Interdisciplinary Oncology Program, Moffitt Cancer Center and Research Institute, University of South Florida, Tampa, FL 33612, USA.
Gynecol Oncol. 2003 Apr;89(1):37-47. doi: 10.1016/s0090-8258(03)00006-4.
We determined the cytotoxic effects BMS 247550 (Epo B), a derivative of epothilone B, on cisplatinum- or paclitaxel-sensitive or -resistant human ovarian cancer cells. Additionally, we determined the effect of Epo B on Apo-2L/TRAIL-induced apoptosis of ovarian cancer cells.
Epo B-induced cytotoxic and cell cycle effects were evaluated by the MTT assay and flow cytometry, respectively. Epo B-induced apoptosis was assessed by immunoblot analyses of the processing and proteolytic activity of caspases, flow cytometric measurement of annexin V staining, and the TUNEL assay. The effects of Epo B and/or Apo-2L/TRAIL on the protein expressions of the death receptors DR4 and DR5 as well as of XIAP and survivin were determined by immunoblot analyses.
In the cell cycle-synchronized ovarian cancer cells, Epo B induced tubulin polymerization and mitotic arrest, followed by apoptosis. This was associated with the cytosolic accumulation of cytochrome (cyt) c and Smac/DIABLO as well as PARP cleavage activity of caspase-3. Epo B was able to exert cytotoxic effects against cisplatinum- and paclitaxel-resistant ovarian cancer cells. Epo B increased the expressions of DR4 and DR5, as well as augmented Apo-2L/TRAIL-induced processing of caspase-8 and Bid. This was associated with more caspase-3 activity, a decline in the intracellular levels of XIAP, cIAP, and survivin, and apoptosis of ovarian cancer cells.
These data support the in vivo testing of Epo B against cisplatinum- and paclitaxel-resistant ovarian cancers, and suggest that a pretreatment with Epo B may sensitize human ovarian cancers to the cytotoxic effects of Apo-2L/TRAIL.
我们测定了埃坡霉素B的衍生物BMS 247550（埃坡霉素B）对顺铂或紫杉醇敏感及耐药的人卵巢癌细胞的细胞毒性作用。此外，我们还测定了埃坡霉素B对Apo-2L/TRAIL诱导的卵巢癌细胞凋亡的影响。
分别通过MTT法和流式细胞术评估埃坡霉素B诱导的细胞毒性和细胞周期效应。通过对半胱天冬酶的加工和蛋白水解活性进行免疫印迹分析、流式细胞术检测膜联蛋白V染色以及TUNEL检测来评估埃坡霉素B诱导的凋亡。通过免疫印迹分析确定埃坡霉素B和/或Apo-2L/TRAIL对死亡受体DR4和DR5以及XIAP和生存素蛋白表达的影响。
在细胞周期同步化的卵巢癌细胞中，埃坡霉素B诱导微管蛋白聚合和有丝分裂停滞，随后发生凋亡。这与细胞色素（cyt）c和Smac/DIABLO的胞质积累以及半胱天冬酶-3的PARP裂解活性有关。埃坡霉素B能够对顺铂和紫杉醇耐药的卵巢癌细胞发挥细胞毒性作用。埃坡霉素B增加了DR4和DR5的表达，并增强了Apo-2L/TRAIL诱导的半胱天冬酶-8和Bid的加工。这与更多的半胱天冬酶-3活性、XIAP、cIAP和生存素细胞内水平的下降以及卵巢癌细胞的凋亡有关。
这些数据支持对埃坡霉素B针对顺铂和紫杉醇耐药的卵巢癌进行体内试验，并表明用埃坡霉素B预处理可能使人类卵巢癌对Apo-2L/TRAIL的细胞毒性作用敏感。
